The centrality of informatics in all aspects of biomedical science and in health care practice highlights the need for well-trained individuals capable of carrying out and leading multidisciplinary and interdisciplinary research in this discipline. This proposal is aimed at continuing and improving upon a Boston-area Biomedical Informatics Research Training (BIRT) program, which has this mission. BIRT brings together in a coordinated program a wide variety of activities already under way at MIT, Harvard, affiliated institutes and area hospitals. Training will focus on three main areas: (1) bioinformatics, (2) clinical/health systems informatics, and (3) public health informatics. Because of complementary predoctoral training support for area (1), BIRT will not duplicate that, but will support training in this area for originally undifferentiated predoctoral students discovering interest in bioinformatics, for transition into the other training program, and for postdoctoral fellows. Besides addressing in-depth needs of each focus area, the goal for BIRT is to provide an integrated and comprehensive approach to addressing common methodologies, infrastructure challenges, and cross-cutting problems, and to develop critical mass and synergies, to enhance mentoring and career development of trainees. The administrative and academic home of the BIRT program is the joint Harvard-MIT Division of Health Sciences and Technology. A new Harvard Medical School Center for Biomedical Informatics will seek to imbue a culture of collaboration and interaction for research and training, through a variety of initiatives. We are requesting support in the BIRT program for 5 predoctoral students and 19 postdoctoral fellows per year, almost all of whom will be in research MS or PhD programs. The wide variety of courses at Harvard and MIT, multiple productive research centers, and strong mentoring records of a distinguished faculty give both depth and breadth to this venue for training. New courses will be developed over the next several years, and the areas of concentration further delineated and strengthened. Continued monitoring of our trainees and graduates will be carried out to aid in program assessment and improvement: